1. Field of the Invention
The present invention relates to a data transmission apparatus which transmits data relating to an image to an ink-jet recording apparatus.
2. Description of Related Art
As an image printed by an ink-jet printer becomes higher in resolution, a size of image data handled by the ink-jet printer increases. Meanwhile, there is known an ink-jet printer of line type which includes a fixed ink-jet head elongated in a direction perpendicular to a paper conveyance direction with its length equal to or larger than a paper width, as disclosed in Japanese Unexamined Patent Publication No. 2007-8175.
For maximizing a characteristic of such a line-type ink-jet printer, a capability of high-speed printing, data transmission between a host and the printer must not be a bottleneck. That is, host-printer data traffic in a unit time must not be lower than maximum data traffic processable in the unit time in the printer. However, because of a structural limitation of an apparatus, host-printer data traffic in a unit time may sometimes be lower than maximum data traffic processable in a unit time in a printer. Such measures have been taken therefor, that image data compressed and downsized in a host are transmitted to a printer which then decompresses (expands) the image data thus received to thereby apparently increase host-printer data traffic in a unit time.